VBA for long if formula

I have a template that looks for a date in serveral different columns and if found, adds five days to show an estimated stock date. my exported report gives the dates as follows 1130813 so that needs formatted as well. so I've come up with this massive ugly formula that causes my computer to freeze for a quite a period of time. not good with VBA and was hoping if something could be written for this formula in order to make this template more user friendly.

so here's the formula... if request date(B) is greater than today's date plus 5 work days, then enter that date
if there's a stock date(AC) enter that date plus 5 days,
if there's 1st order date (AG) enter that date plus 5 work days
if theres a 2nd order date (AI) ""
if theres a 3rd order date (AK) ""

=IFERROR(IF(DATE(MID($B3,2,2)+100,MID($B3,4,2),RIGHT($B3,2))>WORKDAY(NOW(),5),DATE(MID($B3,2,2)+100,MID($B3,4,2),RIGHT($B3,2)),IF(AC3<>0,AC3+5,IF(AG3<>0,WORKDAY(DATE(MID($AG3,2,2)+100,MID($AG3,4,2),RIGHT($AG3,2)),5),IF(AI3<>0,WORKDAY(DATE(MID($AI3,2,2)+100,MID($AI3,4,2),RIGHT($AI3,2)),5),IF(AK3<>0,WORKDAY(DATE(MID($AK3,2,2)+100,MID($AK3,4,2),RIGHT($AK3,2)),5),""))))),"")

thanks in advance for any help!